Aspinall Unit operations update #ColoradoRiver #COriver #aridification

Aspinall Unit Operations update: Turning down to 450 CFS in Black Canyon September 3, 2020 #ColoradoRiver #COriver #aridification

Black Canyon via the National Park Service

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased from 1500 cfs to 1450 cfs on Thursday, September 3rd. Releases are being adjusted to bring flows closer to the baseflow target in the lower Gunnison River. The actual April-July runoff volume for Blue Mesa Reservoir came in at 57% of average.

Flows in the lower Gunnison River are currently above the baseflow target of 890 cfs. River flows are expected to stay at levels above the baseflow target after the release decrease has arrived at the Whitewater gage.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 890 cfs for September.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 500 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 450 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit Operations update: 500 CFS in Black Canyon August 31, 2020 #ColoradoRiver #COriver #aridification

Black Canyon National Park July 2020. Photo credit: Claire Codling/The Department of Interior

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased from 1600 cfs to 1500 cfs on Monday, August 31st. Releases are being adjusted to bring flows closer to the baseflow target in the lower Gunnison River. The actual April-July runoff volume for Blue Mesa Reservoir came in at 57% of average.

Flows in the lower Gunnison River are currently above the baseflow target of 900 cfs. River flows are expected to stay at levels above the baseflow target after the release decrease has arrived at the Whitewater gage.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 890 cfs for September.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 600 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 500 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

#Drought conditions take their toll on Blue Mesa and other area reservoirs — The Montrose Daily Press #ColoradoRiver #COriver #aridification

Blue Mesa Reservoir September 2017

From The Montrose Daily Press (Katharhynn Heidelberg):

As drought conditions hammer the state, area reservoirs are shrinking, with Blue Mesa predicted to end the year at 23 feet below its winter target.

Despite the past winter season bringing nearly average snowpack, runoff throughout the Gunnison Basin fell well below average, according to the U.S. Bureau of Reclamation’s spring forecast and runoff review, provided Aug. 20.

Warm weather brought the snowpack off the mountains early and summer monsoons failed to provide much of a meaningful drink, while extraordinarily hot, dry conditions persist.

For the Uncompahgre Valley Water Users Association’s storage accounts in area reservoirs, conditions are mixed.

Taylor Park Reservoir

Taylor Park Reservoir, which is at about 72 percent of full capacity, is OK for the association, manager Steve Anderson said. The UVWUA’s storage account there is full, with only about 20,000 acre feet used.

“That’s not the case with our storage in Ridgway (Reservoir). We’ll use all our storage this year out of Ridgway. We’ll have to replenish that one with the winter,” Anderson said.

Ridgway Dam

The UVWUA has been running its delivery of water to shareholders at 80 percent. “Which, in a year like we’ve had, is good,” Anderson said. “With the limited supply, we’ve managed to meet demand at 80 percent.”

The largest impoundment managed in the Aspinall Unit, Blue Mesa Reservoir, peaked at 604,000 acre feet, which is 25 feet below full.

As of Aug. 20, the reservoir was at 521,000 acre feet and peak flow targets for the Black Canyon and lower Gunnison River at Whitewater were met, although the base flow targets for Whitewater were lowered under drought rule provisions.

Aspinall Unit

Paonia Reservoir had shriveled to 2 percent of full capacity, while Silver Jack was reported at 46 percent of full.

Paonia is basically empty, but that isn’t unusual, given the dry year, BuRec hydrologist Erik Knight said.

Paonia Reservoir

“They chose to use their full supply of reservoir water as best they could, but being a small reservoir, sometimes it only lasts until August. So it’s not surprising, at least to us or them, that it’s gone already,” he said.

The reservoir is expected to stay empty as long as more senior water right priorities keep the call on the North Fork of the Gunnison, Knight said.

Other reservoirs in the Aspinall fared better, with Ridgway showing at 71 percent, Crystal at 88 percent and Morrow Point at 94 percent.

Bureau of Reclamation’s spring forecast and runoff review noted the early melt-off of the snowpack. Although rains at the start of June kept flows into reservoirs in the Aspinall Unit elevated longer than was expected, those levels plunged to “much below normal” by mid-month. Monsoon activity was anemic, providing “almost no precipitation this summer,” the report also said.

Since runoff ended, hot and dry conditions have prevailed, with near-record dry conditions occurring in April and May. Although those actual conditions caused a higher than normal forecast error, actual runoff volume still fell within the lower range of predictions.

The National Weather Service’s August weather outlook did not hold encouraging news. It found a high probability of below-normal precipitation and above-normal temperatures heading into fall…

The U.S. Drought Monitor shows all of Colorado in at least moderate drought, with Montrose and surrounding counties in either severe or extreme drought.

The monitor on Aug. 20 noted temperature-breaking records in cities across the West, as well as massive wildfires that broke out in California. The monitor’s report, too, calls the monsoon season a “bust” for much of the Southwest.

Aspinall Unit operations update: Releases to turn down 50 CFS on August 17, 2020 #ColoradoRiver #COriver #aridification

Looking downstream from Chasm View, Painted Wall on right. Photo credit: NPS\Lisa Lynch

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased from 1650 cfs to 1600 cfs on Monday, August 17th. Releases are being adjusted to bring flows closer to the baseflow target in the lower Gunnison River. The actual April-July runoff volume for Blue Mesa Reservoir came in at 57% of average.

There is a drought rule in the Aspinall Unit Operations EIS which has changed the baseflow target at the Whitewater gage. The rule states that during Dry or Moderately Dry years, when the content of Blue Mesa Reservoir drops below 600,000 AF the baseflow target is reduced from 1050 cfs to 900 cfs. Therefore, the baseflow target for July and August will now be 900 cfs.

Flows in the lower Gunnison River are currently above the baseflow target of 900 cfs. River flows are expected to stay at levels above the baseflow target after the release decrease has arrived at the Whitewater gage.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 650 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: Baseflow target adjusted to 900 CFS, August 13, 2020 #ColoradoRiver #COriver #aridification

Blue Mesa Reservoir, Curecanti National Recreation Area. Photo credit: Victoria Stauffenberg via Wikimedian Commons

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased from 1600 cfs to 1650 cfs on Thursday, August 13th. Releases are being adjusted to raise flows back to the baseflow target in the lower Gunnison River. The actual April-July runoff volume for Blue Mesa Reservoir came in at 57% of average.

There is a drought rule in the Aspinall Unit Operations EIS which has changed the baseflow target at the Whitewater gage. The rule states that during Dry or Moderately Dry years, when the content of Blue Mesa Reservoir drops below 600,000 AF the baseflow target is reduced from 1050 cfs to 900 cfs. Therefore, the baseflow target for July and August will now be 900 cfs.

Flows in the lower Gunnison River are currently below the baseflow target of 900 cfs. River flows are expected to trend up toward the baseflow target after the release increase has arrived at the Whitewater gage.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 600 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 650 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: ~1050 CFS in the Gunnison Tunnel #ColoradoRiver #COriver #aridification

Gunnison Tunnel via the National Park Service

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased from 1550 cfs to 1600 cfs on Friday, August 7th. Releases are being adjusted to raise flows back to the baseflow target in the lower Gunnison River. The actual April-July runoff volume for Blue Mesa Reservoir came in at 57% of average.

There is a drought rule in the Aspinall Unit Operations EIS which has changed the baseflow target at the Whitewater gage. The rule states that during Dry or Moderately Dry years, when the content of Blue Mesa Reservoir drops below 600,000 AF the baseflow target is reduced from 1050 cfs to 900 cfs. Therefore, the baseflow target for July and August will now be 900 cfs.

Flows in the lower Gunnison River are currently below the baseflow target of 900 cfs. River flows are expected to trend up toward the baseflow target after the release increase has arrived at the Whitewater gage.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 550 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall unit operations update: 500 CFS in Black Canyon starting August 5, 2020

Black Canyon July 2020. Photo credit: Cari Bischoff

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased from 1450 cfs to 1500 cfs on Wednesday, August 5th. Releases are being adjusted to raise flows back to the baseflow target in the lower Gunnison River. The actual April-July runoff volume for Blue Mesa Reservoir came in at 57% of average.

There is a drought rule in the Aspinall Unit Operations EIS which has changed the baseflow target at the Whitewater gage. The rule states that during Dry or Moderately Dry years, when the content of Blue Mesa Reservoir drops below 600,000 AF the baseflow target is reduced from 1050 cfs to 900 cfs. Therefore, the baseflow target for July and August will now be 900 cfs.

Flows in the lower Gunnison River are currently below the baseflow target of 900 cfs. River flows are expected to trend up toward the baseflow target after the release increase has arrived at the Whitewater gage.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 450 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 500 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: 1050 CFS through the Gunnison Tunnel #ColoradoRiver #COriver #aridification

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased from 1550 cfs to 1450 cfs on Tuesday, July 21st. Releases are being adjusted to maintain flows near the baseflow target in the lower Gunnison River. The July 15th runoff forecast for Blue Mesa Reservoir predicts 57% of average for April-July inflows.

There is a drought rule in the Aspinall Unit Operations EIS which has changed the baseflow target at the Whitewater gage. The rule states that during Dry or Moderately Dry years, when the content of Blue Mesa Reservoir drops below 600,000 AF the baseflow target is reduced from 1050 cfs to 900 cfs. Therefore, the baseflow target for July and August will now be 900 cfs.

Flows in the lower Gunnison River are currently above the baseflow target of 900 cfs. River flows are expected to stay at levels above the baseflow target after the release decrease has arrived at the Whitewater gage.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 550 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 450 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Grand opening of the Gunnison Tunnel in Colorado 1909. Photo credit USBR.

Aspinall Unit operations update: 750 CFS in Black Canyon #runoff

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased to 1650 cfs on Tuesday, June 30th. Releases are being adjusted to maintain flows near the baseflow target in the lower Gunnison River. The June 15th runoff forecast for Blue Mesa Reservoir predicts 59% of average for April-July inflows.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay at levels above the baseflow target after the release decrease has arrived at the Whitewater gage.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for June through August.

Currently, Gunnison Tunnel diversions are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 750 cfs. After this release change Gunnison Tunnel diversions will still be around 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 650 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Looking downstream from Chasm View, Painted Wall on right. Photo credit: NPS\Lisa Lynch

Aspinall Unit operations update: 1040 CFS through the Gunnison Tunnel

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased to 1650 cfs on Friday, June 19th. Releases are being increased to maintain flows in the lower Gunnison River. The June 15th runoff forecast for Blue Mesa Reservoir predicts 59% of average for April-July inflows.

Flows in the lower Gunnison River are currently below the baseflow target of 1050 cfs. River flows are expected to return to levels above the baseflow target once the release increase has arrived at the Whitewater gage.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for June through August.

Currently, Gunnison Tunnel diversions are 1040 cfs and flows in the Gunnison River through the Black Canyon are around 430 cfs. After this release change Gunnison Tunnel diversions will still be 1040 cfs and flows in the Gunnison River through the Black Canyon will be around 630 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Gunnison Tunnel via the National Park Service

Aspinall Unit Operations Update

Aspinall Unit April – July, 2020 Forecasted Inflow

From email from Reclamation (Erik Knight):

April – July unregulated inflow volume to Blue Mesa Reservoir
Current Forecast (June 1) = 395,000 AF (59% of average)

Blue Mesa Reservoir current conditions
Content = 595,000 AF (72% full)
Elevation = 7491.7 ft
Inflow = 2200 cfs

Crystal Release = 1450 cfs
Gunnison Tunnel diversion = 1050 cfs
Gunnison River flow = 430 cfs

Spring Operations Summary

Aspinall Unit Operations ROD

Hydrologic Category = Moderately Dry
Peak Flow = 4510 cfs
Duration at Peak Flow = 1 day

Baseflow Target: June/July/Aug = 1050 cfs

(Point of measurement is the Gunnison River near Grand Junction streamgage, commonly called the Gunnison River at Whitewater)

Black Canyon Water Right

Peak Flow = 2840 cfs (24 hour duration)
Shoulder Flow Target = 300 cfs (May 1 – July 25)

(Point of measurement is the Gunnison River below Gunnison Tunnel streamgage at the upstream boundary of Black Canyon of the Gunnison National Park)

Projected Operations

Gunnison River flows (Black Canyon/Gunnison Gorge)
Currently around 400 cfs, possibly increasing to 600-700 cfs during July-August
Projected Blue Mesa Reservoir maximum fill = 620,000 AF at 7495 ft elevation
Projected Blue Mesa Reservoir conditions on Dec 31 = 473,000 AF at 7475 ft elevation

Click here to read the current Aspinall Unit Forecast.

Aspinall Unit dams

@USBR: Aspinall Unit Spring Operations update

Aspinall Unit operations update: April 1st runoff forecast for Blue Mesa Reservoir predicts 78% of average for April-July inflows

Aspinall Unit dams

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased to 1450 cfs on Thursday, April 9th. Releases are being adjusted to accommodate the change in diversions to the Gunnison Tunnel, which will occur on Friday, April 10th. Snowpack in the Upper Gunnison Basin is currently at 101% of normal. The April 1st runoff forecast for Blue Mesa Reservoir predicts 78% of average for April-July inflows.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for April and May.

Currently, Gunnison Tunnel diversions are 720 cfs and flows in the Gunnison River through the Black Canyon are around 430 cfs. After this release change Gunnison Tunnel diversions will be around 920 cfs and flows in the Gunnison River through the Black Canyon will be around 530 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: 550 CFS in the Black Canyon, diversions through the Gunnison Tunnel = 300 CFS

Sunrise Black Canyon via Bob Berwyn

From email from Reclamation Erik Knight:

Releases from the Aspinall Unit will be increased to 1050 cfs on Wednesday, March 25th. Releases are being adjusted to accommodate the change in diversions to the Gunnison Tunnel, which will occur on Thursday, March 26th. Snowpack in the Upper Gunnison Basin is currently at 106% of normal. The March 15th runoff forecast for Blue Mesa Reservoir predicts 78% of average for April-July inflows. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for January through March.

Currently, Gunnison Tunnel diversions are at 300 cfs and flows in the Gunnison River through the Black Canyon are around 400 cfs. After this release change Gunnison Tunnel diversions will be at 500 cfs and flows in the Gunnison River through the Black Canyon will be around 550 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: March 1, 2020 runoff forecast for Blue Mesa Reservoir predicts 78% of average

Blue Mesa Reservoir, Curecanti National Recreation Area. Photo credit: Victoria Stauffenberg via Wikimedian Commons

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased to 700 cfs on Thursday, March 19th. Releases are being adjusted to accommodate the start of diversions to the Gunnison Tunnel and to lower river flows given the below average runoff forecast. Snowpack in the Upper Gunnison Basin is currently at 103% of normal. The March 1st runoff forecast for Blue Mesa Reservoir predicts 78% of average for April-July inflows. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for January through March.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 600 cfs. After this release change Gunnison Tunnel diversions will be at 300 cfs and flows in the Gunnison River through the Black Canyon will be around 400 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: The February 15th runoff forecast for Blue Mesa Reservoir predicts 83% of average for April-July inflows

Aspinall Unit dams

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased to 600 cfs on Wednesday, February 26th. Snowpack in the Upper Gunnison Basin is currently at 103% of normal. The February 15th runoff forecast for Blue Mesa Reservoir predicts 83% of average for April-July inflows. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for January through March.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 800 cfs. After this release change Gunnison Tunnel diversions will still be at zero and flows in the Gunnison River through the Black Canyon will be around 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: Streamflow forecast for April-July = 87% of average

Gunnison River Basin High/Low graph January 27, 2020 via the NRCS.

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased to 800 cfs on Wednesday, January 29th. Snowpack in the Upper Gunnison Basin is currently at 106% of normal. The Jan 15th runoff forecast for Blue Mesa Reservoir predicts 87% of average for April-July inflows. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for January through March.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 1100 cfs. After this release change Gunnison Tunnel diversions will still be at zero and flows in the Gunnison River through the Black Canyon will be around 800 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

This scheduled release change is subject to changes in river flows and weather conditions. For questions or concerns regarding these operations contact Erik Knight at (970) 248-0629 or e-mail at eknight@usbr.gov

Colorado Drought Monitor January 21, 2020.

Montrose: Aspinall Unit operations meeting January 23, 2020 #ColoradoRiver #COriver #aridification

From email from Reclamation (Erik Knight):

The next Aspinall Operations meeting will be on Thursday, January 23rd, at the Holiday Inn Express in Montrose. Start time is 1:00.

Aspinall Unit

Aspinall Unit operations update: Blue Mesa Reservoir within one foot of icing target

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit were decreased to 1100 cfs on Thursday, January 2nd. Blue Mesa Reservoir elevation ended the year within a foot of the icing target. Releases will be maintained at this level for the near future with possible adjustments made when new runoff forecast information becomes available. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for January through March.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 1100 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Blue Mesa Reservoir

Aspinall Unit operations update: Blue Mesa releases to be bumped up to meet reservoir icing targets

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased to 1600 cfs on Monday, December 9th. Blue Mesa Reservoir elevation remains above the winter icing target level. Releases will be maintained at this level with the goal of lowering the reservoir to the icing target elevation of 7490 feet by December 31st. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for September through December.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 1000 cfs. After this release change Gunnison Tunnel diversions will still be at zero and flows in the Gunnison River through the Black Canyon will be around 1600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit

Aspinall Unit operations update: Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs

Gunnison River Basin. By Shannon1 – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=69257550

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased by 200 cfs, today, September 30th. Releases will be decreased by 200 cfs late Friday, October 4th. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for September through December.

Currently, diversions into the Gunnison Tunnel are 1040 cfs and flows in the Gunnison River through the Black Canyon will increase to 800 cfs today. At the end of this week Gunnison Tunnel diversions will still be 1040 cfs and flows in the Gunnison River through the Black Canyon will return to 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall unit operations update: Flows in the Gunnison Tunnel ~= 1030 CFS

Grand opening of the Gunnison Tunnel in Colorado 1909. Photo credit USBR.

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased by 100 cfs, today, September 9th. Reservoir contents at Morrow Pt and Crystal have sufficiently recovered to allow for higher releases. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for September through December.

Currently, diversions into the Gunnison Tunnel are 1030 cfs and flows in the Gunnison River through the Black Canyon are around 500 cfs. After this release change Gunnison Tunnel diversions will still be 1030 cfs and flows in the Gunnison River through the Black Canyon will be around 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit Operations update: Streamflow in the Black Canyon ~515 cfs

From email from the Bureau of Reclamation (Ryan Christianson):

Releases from the Aspinall Unit will be decreased by 100 cfs at approximately 10am on Tuesday, September 3rd. Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for September. This release decrease will allow for the recovery of storage in Crystal Reservoir that was utilized in response to upstream facility outages.

Currently, diversions into the Gunnison Tunnel are approximately 1200 cfs and flows in the Gunnison River through the Black Canyon are around 615 cfs. After this release change, the Gunnison Tunnel diversions will remain near 1200 cfs and flows in the Gunnison River through the Black Canyon will be around 515 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Looking downstream from Chasm View, Painted Wall on right. Photo credit: NPS\Lisa Lynch

The August “#GunnisonRiver Basin News” is hot off the presses

Click here to read the newsletter from the Gunnison Basin Roundtable. Here’s an excerpt:

August in the Basin: High and Dry!

Bountiful snowmelt and increased soil moisture conditions, resulted in “boomer” inflows, boosting basin reservoirs levels and causing an amazing recovery from last year’s low levels – this included Blue Mesa, Colorado’s largest reservoir – with over 160 percent of average inflow volume. Although most of the snow has melted, the Upper Basin rivers are still flowing at higher than average rates, even in the face of drying conditions (July and August precipitation has been generally below average).

Also, very importantly Lake Powell – the Upper Basin’s largest water storage and management facility received an inflow volume of 145% of average.

Current conditions and Aspinall Unit operations

Aspinall Unit dams

@USBR: The next Aspinall Operations meeting will be held on Thursday, August 15th, at the Elk Creek Visitor Center at Blue Mesa Reservoir. Start time is 1:00 PM

Aspinall Unit operations update: Gunnison Tunnel diversions = 950 cfs, Gunnison River through the Black Canyon = 2550 cfs

Gunnison Tunnel via the National Park Service

From email from Reclamation (Ryan Christianson):

Releases from the Aspinall Unit were increased by 500 cfs beginning on Friday, July 26th and are scheduled to continue at that rate into the near future in order to prevent Blue Mesa Reservoir from overfilling. At the current inflow and release rate it is projected that Blue Mesa Reservoir would begin spilling, as the reservoir is now full. The current forecast for the April-July runoff volume for Blue Mesa Reservoir is 1,075,000 AF of inflow, which is 159% of average. Flows in the lower Gunnison River are currently above the baseflow target of 1500 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1500 cfs for July and August.

Currently, diversions into the Gunnison Tunnel are 950 cfs and flows in the Gunnison River through the Black Canyon are around 2550 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: 2150 cfs expected in the Black Canyon

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased by 650 cfs between Tuesday and Wednesday, July 9 and 10. This release increase is necessary to prevent Blue Mesa Reservoir from overfilling. At the current release rate it is projected that Blue Mesa Reservoir would spill within 2 weeks. The current forecast for the April-July runoff volume for Blue Mesa Reservoir is 1,060,000 AF of inflow, which is 157% of average. Flows in the lower Gunnison River are currently above the baseflow target of 1500 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1500 cfs for July and August.

Currently, diversions into the Gunnison Tunnel are 850 cfs and flows in the Gunnison River through the Black Canyon are around 1500 cfs. After this release change Gunnison Tunnel diversions will still be 850 cfs and flows in the Gunnison River through the Black Canyon will be around 2150 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Black Canyon of the Gunnison

Aspinall Unit Spring Peak Operations Update

From email from Reclamation (Erik Knight):

The spring peak operation is nearing completion. The peak release period of the spring peak operation has concluded. Flows at the Whitewater gage were over 14,350 cfs for six days and a peak daily flow of 16,500 cfs occurred on June 9th.

The ramp down period has begun and releases will continue to be decreased through Thursday, June 20th. The ramp down schedule is shown below. Daily flows for the Gunnison River below the Gunnison Tunnel should be considered as approximations. Actual flows may vary from the numbers below if side inflows to Crystal Reservoir increase or decrease the spill rate beyond what is currently forecast.

#Runoff/#Snowpack news: It looks like Blue Mesa Reservoir will fill this year

From The Grand Junction Daily Sentinel (Dennis Webb):

Aldis Strautins, hydrologist for the National Weather Service in Grand Junction, said so far snow has been melting off in a manageable fashion, with some minor flooding in lowland locations but nothing serious so far.

“We’re not totally out of the woods yet. It bears monitoring and keeping aware of the situation,” he said.

He said the Colorado River is coming up and may peak locally around Sunday. Andy Martsolf, emergency services director for the Mesa County Sheriff’s Office, said flows on the Colorado River at the state line are expected to peak at about 36,000 cubic feet per second this weekend. That’s up considerably from the 24,900 cfs being reported there by the U.S. Geological Survey Wednesday.

Officials expect a possible second peak later this month.

The Gunnison River already is cranking, but that’s by design, under the operational protocol for the Aspinall Unit dams on the river. Erik Knight, a hydrologist with the Bureau of Reclamation, said releases began on Saturday in an attempt to hit a target goal of flows of 14,350 cfs for 10 days on the lower Gunnison at Whitewater, to help critical habitat for endangered fish in that stretch.

He said it appears flows will fall 1,000 cfs short of that goal.

The National Weather Service has issued a flood advisory in the lower Gunnison River due to the extra water releases affecting river levels there. Strautins said it wasn’t a flood warning, but an effort to make people aware of dangers such as banks giving way due to the high water.

Knight said it doesn’t appear that flows through Delta will exceed 13,000 cfs during the 10-day release. That’s below the level at which the Bureau of Reclamation would cut back releases during the 10-day period to protect the community from flooding.

Wilma Erven, Delta’s parks, recreation and golf director, said some water is showing up in a park at the confluence of the Gunnison and Uncompahgre rivers, something that can occur in years like this one…

Strautins pointed to a mix of warmer and cooler weather in the forecast in coming days as opposed to a prolonged hot stretch that could drive water levels particularly high, with cloud cover also expected to moderate melting of snow.

Knight, who several months ago could hardly have imagined Blue Mesa Reservoir filling this year after last year’s low snowpack and drought, said it now appears almost certain to fill…

…the snowpack levels remaining in areas such as southwest Colorado are impressive, as evidenced by the mere fact that many sites that normally are dry by now still have snow.

According to one of the data sets [Brian] Domonkos uses, current snowpack levels in those combined basins and in the Gunnison basin are the second-highest on record, he said. But peak levels this year in basins in western Colorado don’t compare nearly as well to other high snowpack years, with the southwest Colorado basins ranking perhaps fourth or fifth, and other basins not coming in that high, Domonkos said.

He said one of his statistical tools indicates there are about 12.3 inches of snow water equivalent left in the Gunnison basin, which peaked at 24 inches.

“So we’re halfway through the melt of that peak snowpack,” he said.

The Colorado basin has about 11 inches of snow water equivalent left, after peaking at about 20 inches, Domonkos said.

He said snowpack normally melts at a rate of an inch a day or a little less of snow water equivalent.

“So snowpack on average probably won’t be hanging around too much longer,” he said.

While more than half of the Colorado basin’s snowpack already is melted, that snowpack was above-average, and Martsolf said the remaining snowpack is still about 71 percent of an average peak snowpack for the basin.

“We’re definitely melted off from where we would be for a seasonal peak but we still have a ways to go,” he said…

Nowhere in western Colorado is the combined threat of rising rivers and avalanche debris causing more concern than in Hinsdale County. Federal, state and county funding is paying the nearly $1 million cost for the ongoing, emergency removal of the historic, defunct Hidden Treasure Dam. While it no longer holds water, there’s concern that avalanche debris washing down Henson Creek combined with high water flows could destroy it, releasing water and debris and causing downstream flooding…

Both Henson and the Lake Fork of the Gunnison creeks pose threats to Lake City. Lyon said there’s currently no flooding occurring, but creek levels have come up considerably in recent days. Warming temperatures and possible rainstorms both could influence what ultimately occurs in coming days and weeks.

#Runoff news: Inflows to Blue Mesa Reservoir = ~200,000 acre-feet as of May 20, 2019

From The Vail Daily (Scott N. Miller) via The Aspen Times:

At the Eagle River Water & Sanitation District’s May 20 State of the River gathering, participants heard a presentation from Karl Wetlaufer, a hydrologist and assistant supervisor with the U.S. Department of Agriculture’s Natural Resources Conservation Service.

Wetlaufer talked about state and regional snowpack and provided some streamflow forecasts. The news was good on both topics.

It isn’t just the Eagle River drainage that’s had a good snow year. Across Colorado, the average “snow water equivalent” in the snowpack stands at 186 percent of the 30-year median. After the drought of 2018, that’s fantastic news.

According to Wetlaufer, Southern Colorado — the part of the state that most needed a big snow year — was the area where the snowpack is greatest. The snowpack in the San Juan, Dolores, Animas and San Juan River basins — closest to the Four Corners area — stood at 294 percent of the median on May 20.

Wetlaufer said that runoff so far has added about 200,000 acre feet of water to one of the state’s biggest reservoirs, Blue Mesa, near Gunnison. At the end of 2018, that reservoir was at its lowest level since 1984.

All the good news across the state is good news to local fishing guides and raft companies.

Sage Outdoor Adventures has a permit to raft Gore Creek through Vail. That didn’t happen last year. Cole Bangert of Sage said in an average year, the company can run raft trips through Vail for three or four weeks per season, mostly in June.

Bangert said he expects a longer season this year, due both to abundant snow and a slow melt so far.

Clear Creek Canyon via Bob Berwyn

From CBS 4 Denver (Michael Abeyta):

[Bruce Becker] says with all the snow we’ve been getting, water flow in the state’s rivers could be the highest we’ve seen since 2011 or 2013…

Add to that the cool start we’ve gotten to the season and conditions are almost perfect for a long and fun season…

Whitewater rafting and kayaking outfitters across the state hope Becker is right because last year’s hot dry summer and winter really hurt business.

“Our other outfitters in southwest Colorado practically had no season. My season on Clear Creek which is my main run was cut a month short and when you only have three months, losing one month hurts.”

On Sunday, a man was in Becker’s office booking a trip for late July. With folks already booking their trips months in advance, he is optimistic this summer on the river will be a good one for everyone.

Aspinall Unit operations update: Crystal Reservoir spill forecasted for May 27, 2019

Aspinall Unit

From email from Reclamation (Erik Knight):

The May 15th forecast for the April – July unregulated inflow volume to Blue Mesa Reservoir is 990,000 acre-feet. This is 147% of the 30 year average. Snowpack in the Upper Gunnison Basin peaked at 143% of average. Blue Mesa Reservoir current content is 457,000 acre-feet which is 55% of full. Current elevation is 7473.2 ft. Maximum content at Blue Mesa Reservoir is 829,500 acre-feet at an elevation of 7519.4 ft.

Based on the May forecasts, the Black Canyon Water Right and Aspinall Unit ROD peak flow targets are listed below:

Black Canyon Water Right
The peak flow target is equal to 7,158 cfs for a duration of 24 hours.
The shoulder flow target is 966 cfs, for the period between May 1 and July 25.

Aspinall Unit Operations ROD
The year type is currently classified as Moderately Wet.
The peak flow target will be 14,350 cfs and the duration target at this flow will be 10 days.
The half bankfull target will be 8,070 cfs and the duration target at this flow will be 20 days.
(The criteria have been met for the drought rule that allows half-bankfull flows to be reduced from 40 days to 20 days.)

Pursuant to the Aspinall Unit Operations ROD, releases from the Aspinall Unit will be made in an attempt to match the peak flow of the North Fork of the Gunnison River to maximize the potential of meeting the desired peak at the Whitewater gage, while simultaneously meeting the Black Canyon Water Right peak flow amount. The latest forecast for flows on the North Fork of the Gunnison River keeps river flows below their projected peak flow level for most of the 10 day forecast period. Warmer weather and higher flows are forecast to return by the first days of June.

Therefore ramp up for the spring peak operation will begin on Wednesday, May 22nd, with the intent of timing releases with this potential higher flow period on the North Fork of the Gunnison River. Releases from Crystal Dam will be ramped up according to the guidelines specified in the EIS, with 2 release changes per day, until Crystal begins to spill. The release schedule for Crystal Dam is:

Crystal Dam will be at full powerplant and bypass release on May 26th. Crystal Reservoir will begin spilling by May 27th and the peak release from Crystal Dam should be reached on May 30th or 31st. The flows in the Gunnison River after that date will be dependent on the timing of the spill and the level of tributary flow contribution. Estimates of those numbers will be determined in the upcoming days.

The current projection for spring peak operations shows flows in the Gunnison River through the Black Canyon between 7,000 cfs and 8,000 cfs for 10 days in order to achieve the desired peak flow and duration at Whitewater. Actual flows will be dependent on the downstream contribution of the North Fork of the Gunnison River and other tributaries. Higher tributary flows will lead to lower releases from the Aspinall Unit and vice versa.

Crystal dam spilling May 2009

Aspinall unit operations update: Blue Mesa Reservoir is currently projected to fill to an approximate peak content of 795,000 acre-feet

Blue Mesa Reservoir

From email from Reclamation (Erik Knight):

The May 1st forecast for the April – July unregulated inflow volume to Blue Mesa Reservoir is 970,000 acre-feet. This is 144% of the 30 year average. Snowpack in the Upper Gunnison Basin peaked at 143% of average. Blue Mesa Reservoir current content is 384,000 acre-feet which is 46% of full. Current elevation is 7462 ft. Maximum content at Blue Mesa Reservoir is 829,500 acre-feet at an elevation of 7519.4 ft.

Based on the May 1st forecast, the Black Canyon Water Right and Aspinall Unit ROD peak flow targets are listed below:

Black Canyon Water Right
The peak flow target is equal to 7,158 cfs for a duration of 24 hours.
The shoulder flow target is 966 cfs, for the period between May 1 and July 25.

Aspinall Unit Operations ROD
The year type is currently classified as Moderately Wet.
The peak flow target will be 14,350 cfs and the duration target at this flow will be 10 days.
The half bankfull target will be 8,070 cfs and the duration target at this flow will be 20 days.
(The criteria have been met for the drought rule that allows half-bankfull flows to be reduced from 40 days to 20 days.)

Projected Spring Operations
During spring operations, releases from the Aspinall Unit will be made in an attempt to match the peak flow of the North Fork of the Gunnison River to maximize the potential of meeting the desired peak at the Whitewater gage, while simultaneously meeting the Black Canyon Water Right peak flow amount. The magnitude of release necessary to meet the desired peak at the Whitewater gage will be dependent on the flow contribution from the North Fork of the Gunnison River and other tributaries downstream from the Aspinall Unit. Current projections for spring peak operations show that flows in the Gunnison River through the Black Canyon could be over 8,000 cfs for 10 days in order to achieve the desired peak flow and duration at Whitewater. With this runoff forecast and corresponding downstream targets, Blue Mesa Reservoir is currently projected to fill to an elevation of around 7515.5 feet with an approximate peak content of 795,000 acre-feet.

Aspinall Unit operations update: 960 CFS in Black Canyon

Sunrise Black Canyon via Bob Berwyn

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased by 130 cfs on Friday, May 3rd. This will bring flows in the Gunnison River through the Black Canyon up to shoulder flow levels, as described in the decree for the Black Canyon water right. The current forecast for the April-July runoff volume for Blue Mesa Reservoir is 970,000 AF of inflow, which is 144% of average. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for May.

Currently, diversions into the Gunnison Tunnel are 680 cfs and flows in the Gunnison River through the Black Canyon are around 830 cfs. After this release change Gunnison Tunnel diversions will still be 680 cfs and flows in the Gunnison River through the Black Canyon will be around 960 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: 825 cfs through Black Canyon

Looking downstream from Chasm View, Painted Wall on right. Photo credit: NPS\Lisa Lynch

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased by 250 cfs on Wednesday, May 1st. This will bring flows in the Gunnison River through the Black Canyon up to shoulder flow levels, as described in the decree for the Black Canyon water right. The current forecast for the April-July runoff volume for Blue Mesa Reservoir is 860,000 AF of inflow, which is 127% of average. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for April and May.

Currently, diversions into the Gunnison Tunnel are 675 cfs and flows in the Gunnison River through the Black Canyon are around 575 cfs. After this release change Gunnison Tunnel diversions will still be 675 cfs and flows in the Gunnison River through the Black Canyon will be around 825 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

@USBR: Aspinall Unit Forecast for Spring Operations: Current projected inflow to Blue Mesa Reservoir = 925,000 acre-feet

From email from Reclamation (Erik Knight):

The April 1 forecast for the April – July unregulated inflow volume to Blue Mesa Reservoir is 925,000 acre-feet. This is 137% of the 30 year average. Snowpack in the upper Gunnison River basin is currently 132% of average. Blue Mesa Reservoir current content is 259,000 acre-feet which is 31% of full. Current elevation is 7440 feet. Maximum content at Blue Mesa Reservoir is 829,500 acre-feet at an elevation of 7519.4 feet.

Black Canyon Water Right
The peak flow and shoulder flow components of the Black Canyon Water Right will be determined by the May 1 forecast of the April – July unregulated inflow volume to Blue Mesa Reservoir. If the May 1 forecast is equal to the current forecast of 925,000 acre-feet of runoff volume, the peak flow target will be 6,513 cfs for a duration of 24 hours. The shoulder flow target will be 915 cfs, for the period between May 1 and July 25. The point of measurement of flows to satisfy the Black Canyon Water Right is at the Gunnison River below Gunnison Tunnel streamgage at the upstream boundary of Black Canyon of the Gunnison National Park.

Aspinall Unit Operations ROD
Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the peak flow and duration flow targets in the lower Gunnison River, as measured at the Whitewater gage, will be determined by the forecast of the April – July unregulated inflow volume to Blue Mesa Reservoir and the hydrologic year type. At the time of the spring operation, if the forecast is equal to the current forecast of 925,000 acre-feet of runoff volume, the hydrologic year type will be set as Moderately Wet. Under a Moderately Wet year the peak flow target will be 14,350 cfs and the duration target at this flow will be 10 days. The duration target for the half-bankfull flow of 8,070 cfs will be 20 days. The criteria have been met for the drought rule that allows half-bankfull flows to be reduced from 40 days to 20 days.

Projected Spring Operations
During spring operations, releases from the Aspinall Unit will be made in an attempt to match the peak flow of the North Fork of the Gunnison River to maximize the potential of meeting the desired peak at the Whitewater gage, while simultaneously meeting the Black Canyon Water Right peak flow amount. The magnitude of release necessary to meet the desired peak at the Whitewater gage will be dependent on the flow contribution from the North Fork of the Gunnison River and other tributaries downstream from the Aspinall Unit. Current projections for spring peak operations show that flows in the Gunnison River through the Black Canyon could be over 7,500 cfs for 10 days in order to achieve the desired peak flow and duration at Whitewater. With this runoff forecast and corresponding downstream targets, Blue Mesa Reservoir is currently projected to fill to an elevation of around 7500 feet with an approximate peak content of 660,000 acre-feet.

Aspinall Unit dams

#Runoff in #ColoradoRiver basin likely below-average, @usbr official warns — @AspenJournalism #snowpack #COriver #aridification #cwcac2019

A big beach on the banks of the Green River in September 2018, one of the lowest months on record for inflow into Lake Powell. Runoff is 2019 is expected to be better than 2018, but still below average due to dry soil conditions in the area drained by the Green and Colorado river systems. Photo: Brent Gardner-Smith/Aspen Journalism

From Aspen Journalism (Brent Gardner-Smith):

The regional director of the Upper Colorado River Basin for the Bureau of Reclamation told water managers and users last week to expect below-average runoff this year, despite encouraging snowfall this winter.

Brent Rhees — who oversees the federal reservoirs in the upper basin for the Bureau of Reclamation, including Lake Powell, Flaming Gorge and Blue Mesa — said that although this winter’s snowfall, or “snow water equivalent,” in the upper basin above Lake Powell was now above average (109 percent on Feb. 7) the parched ground left in the wake of a hot, dry 2018 likely would soak up a lot of the resultant moisture in the spring.

As such, this year’s runoff is not expected to reach the average level, although storms in February and March could push it up to the 80 percent range.

“What we’re suffering from is last year’s dry year,” Rhees told the members of the Colorado Water Congress on Feb. 1. “And so, the runoff that is forecast is not that great. Last year, you all remember, it was the third-lowest on record inflow into Lake Powell. So, it’s not looking really good.”

Since Rhees’ remarks, it has been snowing a lot in Colorado, and the snowpack in the Roaring Fork River basin was at 115 percent of average on Feb. 6. But, again, Rhees was looking at future runoff over a thirsty landscape.

The inflow into Lake Powell during water year 2018 (Oct. 1 to Sept. 30) totaled about 4.5 million acre-feet, or MAF, while about 9 MAF was released from Glen Canyon Dam to run down the Colorado River and into Lake Mead, Rhees said.

“So, the math is pretty simple, isn’t it?” Rhees said. “More went out than came in. And so, we saw a significant drop in reservoir elevation.”

As of Jan. 1, the Bureau of Reclamation forecast that 6.98 MAF, or 64 percent of average, would most likely flow into Lake Powell, but releases from Lake Powell are expected to be about 8.6 MAF.

“We’re going to release a little bit more than comes in, likely this year,” Rhees said.

That means Lake Powell is expected to continue to shrink in 2019.

On Feb. 3, the elevation of the reservoir, as measured against the upstream face of Glen Canyon Dam, was 3,575 feet above sea level, or 39 percent full, and held 9.6 MAF.

A diagram showing the intake structures on the upstream face of the Glen Canyon Dam, which forms Lake Powell.

Three efforts

The first ongoing effort to bolster water levels in Lake Powell is weather modification in the form of cloud seeding.

Rhees said the federal government’s position on funding cloud seeding has moved from funding only research to funding active operations, too.

“That’s good news from my perspective,” he said.

The second effort is “drought-response operations,” which will begin if Lake Powell drops to the triggering elevation of 3,525 feet, or 35 feet above minimum power pool (which it is not yet forecasted to do in either 2019 or 2020).

But should the reservoir hit 3,525 feet, the drought-response operations will entail releasing up to 2 MAF of water from federal reservoirs in the upper basin, primarily from Flaming Gorge Reservoir on the Green River, which can hold 3.7 MAF; Blue Mesa Reservoir on the Gunnison River, which can hold 829,500 acre-feet; and Navajo Reservoir on the San Juan River, which can hold 1.69 MAF.

Rhees said Flaming Gorge is “the one that can have the biggest impact, (but) all (federal) reservoirs can participate in propping up that minimum power pool of 3,490 (feet).”

He also said the releases from the reservoirs would be “indiscernible” to river users and the water would not come down the river in a big wave of water, as some might imagine.

“You won’t know, if you are on the river, that it’s even happening,” he said.

The third effort to add more water to the river system is “demand management,” or a purposeful reduction in the amount of water diverted from rivers and put to a consumptive use, such as growing a crop or a lawn.

Voluntary demand-management programs are now being investigated in Colorado, Utah and Wyoming, and the water saved by irrigators fallowing fields — for money — is to be stored in a new regulatory pool of up to 500,000 acre-feet in Lake Powell.

Editor’s note: Aspen Journalism covers rivers and water in collaboration with The Aspen Times and other Swift Communications newspapers. The Times published this story on Thursday, Feb. 7, 2018.

Aspinall Unit operations meeting January 17, 2019

From email from Reclamation (Erik Knight):

The next Aspinall Operations meeting will be held on January 17th in Montrose at the Holiday Inn Express. The meeting will start at 1:00.

Aspinall Unit

Western Slope Water Summit recap

Gunnison River Basin via the Colorado Geological Survey

From The Montrose Daily Press (Andrew Kiser):

Farmers have a taxing job growing crops due to water rights and, now, a multi-year drought, said Montrose County Commissioner Sue Hansen.

Those concerns were brought to the forefront during the Western Slope Water Summit — held Tuesday morning at the Montrose County Event Center. The group mostly discussed the water shortage and the drought crisis on the Western Slope.

Hansen said the county wanted farmers and producers to know about those challenges and about other potential obstacles under the new drought contingency plan…

As far as the effects of the drought, residents need look no further than the Gunnison River.

According to the Colorado River District, the river is snared between climate change-driven drought and overuse by the Lower Basin states to which a sure quantity of water must be transported each year, under the 1922 Colorado River Compact…

Andy Mueller, Colorado River District general manager, added the state’s farmers “are battling urban areas for their livelihood.”

“I think we, as an Upper Basin, need to put the hammer down and need to call them out in terms of what they’re doing,” he said.

Blue-Green algae found in Blue Mesa Reservoir

Graphic credit: Climate Central

From the Associated Press via The Grand Junction Daily Sentinel:

The National Park Service says unsafe levels of a type of algae that can be harmful to humans have been found in the water of a central Colorado reservoir.

Park officials said they detected the presence of toxins that can be produced by algae blooms in water samples taken from Blue Mesa Reservoir.

The agency advised visitors to avoid contact with shallow waters in an area known as the Iola Basin and to avoid mats of algae throughout the reservoir.

The reservoir is part of Curecanti National Recreation Area west of Gunnison, Colorado.

Harmful blue-green algae is natural to the area but can spread quickly in warm, shallow water.

Forecast for Blue Mesa Reservoir = record low territory #ColoradoRiver #COriver #aridification

From The Colorado Springs Gazette (Liz Forster):

The Blue Mesa Reservoir, which feeds into the Colorado River, is at 39 percent capacity, according to the Bureau of Land Reclamation. The last time the reservoir west of Gunnison was at a similar level was in 1987, said Sandra Snell-Dobert, a spokeswoman for the Black Canyon of the Gunnison National Park and Curecanti National Recreation Area.

Soon, water levels are expected to drop to the point where launching and operating boats at most ramps won’t be possible, Snell-Dobert said

Low water levels and rising temperatures also have allowed for blue-green algae blooms. Although no direct environmental impacts have not been observed, some species of this algae can produce toxins that are harmful to dogs.

The Gunnison River Basin varied between 50 percent and 80 percent of its average snowpack this winter, hitting a low of 51.6 percent Dec. 20 and a peak of 79.81 percent April 20.

Other Colorado River reservoirs are facing similar shortages.

Lake Powell and Lake Mead in Arizona dropped to dangerous levels this week because of what scientists are calling the effects of the Colorado River’s worsening “structural deficit,” The Associated Press reported.

Lake Powell and Lake Mead hit 48 percent and 38 percent capacity, respectively.

The Colorado River basin, which feeds lakes Mead and Powell, has been drying out over the last two decades, scientists said. With the demands from farms and cities exceeding the available water supply, the strains on the river and reservoirs are being compounded by growing population, drought and climate change.

From Colorado Public Radio (Grace Hood):

The Colorado Division of Water Resources reports the basins were 50 percent full at the end of August, in contrast to last year’s 120 percent average capacity. The average for this time of year is about 82 percent.

The Yampa-White, San Juan-Dolores, Rio Grande, Gunnison and Colorado river basins are classified as being in either “moderate” or “severe drought.”

The Blue Mesa Reservoir near Gunnison on the Curecanti National Recreation Area, is near historic lows — it’s 39 percent full — and has closed almost all its boat ramps. Iola closed Thursday night, the Lake Fork ramp closes Monday. That will leave only the Elk Creek ramp on the reservoir’s north shore along Hwy. 50 open, said recreation area spokeswoman Sandra Snell-Dobert. “Elk Creek, the ramp will remain open as long as we can keep it open.”

The last time water levels were this low on the reservoir was in 1987, Snell-Dobert said. Blue Mesa usually only closes if there’s not enough staff or if the reservoir freezes. The reservoir levels now have also caused some abnormal boating hazards.

“Mostly it’s rocks that are becoming exposed as the water level decreases. There are a lot of rock promontories and islands, and those kinds of things that we haven’t seen in a long time,” she said. But despite the boating restrictions, Snell-Dobert said shoreline fishing, kayaking, canoeing and other hand-launched, non-motorized boating are still allowed at the reservoir.

Aspinall Unit operations update: Inflows to Blue Mesa Reservoir April-July = 35% of average

Blue Mesa Reservoir

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased by 75 cfs on Sunday, September 9th. Releases are being decreased in order to bring flows in the lower Gunnison River closer to the baseflow target while conserving storage in Blue Mesa Reservoir. The actual April-July runoff volume for Blue Mesa Reservoir was 237,500 AF of inflow, which is 35% of average.

Flows in the lower Gunnison River are currently above the baseflow target of 890 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 890 cfs for September.

Currently, diversions into the Gunnison Tunnel are 1000 cfs and flows in the Gunnison River through the Black Canyon are around 575 cfs. After this release change Gunnison Tunnel diversions will still be 1000 cfs and flows in the Gunnison River through the Black Canyon will be around 500 cfs.

Aspinall Unit operations update: 630 CFS in Black Canyon

Looking downstream from Chasm View, Painted Wall on right. Photo credit: NPS\Lisa Lynch

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased by 100 cfs on Monday, July 23rd . Releases are being decreased to retain storage in Blue Mesa Reservoir while still reaching the baseflow target. A recent streamflow measurement has revealed that the Gunnison River at the Whitewater gage was flowing ~100 cfs higher than what the gage was reporting. The release adjustment at Crystal will bring those river flows back down closer to the baseflow target. The latest runoff volume forecast for Blue Mesa Reservoir projects 240,000 AF of inflow between April and July, which is 36% of average.

Flows in the lower Gunnison River are currently above the baseflow target of 900 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 900 cfs for July. There is a provision in the EIS which allows the baseflow target to be reduced from 1050 cfs to 900 cfs when the content in Blue Mesa Reservoir is below 600,000 AF. The current content of Blue Mesa Reservoir is 427,000 AF and dropping.

Currently, diversions into the Gunnison Tunnel are 1050 cfs and flows in the Gunnison River through the Black Canyon are around 730 cfs. After this release change Gunnison Tunnel diversions will still be 1050 cfs and flows in the Gunnison River through the Black Canyon will be around 630 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Ouray “State of the River” meeting recap: “We can survive one bad drought” — Bob Hurford

Uncompahgre River Valley looking south

From The Telluride Daily Planet (Tanya Ishikawa):

[Bob] Hurford’s general sentiment about this year’s drought was shared by all who presented reports at the Ouray State of the Rivers meeting at the Ouray County 4H Event Center May 16. The presentations came two weeks after Gov. John Hickenlooper activated the Colorado Drought Mitigation and Response Plan for the agricultural sector in 34 of the state’s 64 counties, including San Miguel, Ouray, Montrose, and Delta counties…

Hurford explained that over half of the Rocky Mountains’ water supply is in its snowpack. As of April 1, Colorado’s snowpack was 68 percent of average and 64 percent of last year’s. Data maps show that the April 1 snowpack was between 50 percent and 69 percent for Ouray and Montrose counties, and below 50 percent for San Miguel County. Division 4, the eastern area around Gunnison, has the most snowpack; the San Juan Mountains have the least, with snowpack above Ridgway Reservoir at just 46 percent of average.

Colorado, Utah, Arizona and California had the lowest amount of precipitation in the U.S. this winter, and those four states — plus Nevada and New Mexico — had the highest temperatures from November 2017 to January 2018, according to statistics in Hurford’s report.

Data from reservoirs in October 2017 show that Colorado had one of its best years with close to 120 percent of average water levels statewide, 100 percent of average in Division 4 and around 116 percent of average in Ridgway Reservoir. Over the last two decades, reservoirs were at or above 100 percent for 11 years.

“We can survive one bad drought. Two bad droughts in a row and that gets us,” Hurford said.

Ridgway Reservoir Dam Superintendent Tony Mitchell, of Tri-County Water Conservancy District, showed National Weather Service forecast data that estimated January-April 1 flows into the reservoir at 88 percent of average in 2016, 111 percent in 2017 and 49 percent in 2018. For the period of April 1 through July, the main runoff season, flow estimates were 92 percent of average in 2016, 96 percent in 2017 and 40 percent in 2018.

Responding to a question about why the reservoir has looked lower than usual this spring, Tri-County Water Conservancy District Manager Mike Berry said late-season releases to the Uncompahgre Valley Water Users Association (UVWUA) were larger than usual last year, precipitation was low last summer and storage levels are kept lower than normal to avoid water spilling over the dam, which would send non-native fish into the Uncompahgre River, endangering the trout there.

UVWUA Manager Steve Andersen, who is also a director on the Colorado Water Conservation Board, said, “My association will be OK this year. There’s not as much water as we would like to have, but we will be able to make a crop this year.”

However, to ensure its downstream water users have enough water, the association in Montrose may have to put a call on water use later in the season, shutting headgates to irrigators upstream in Ouray County (who have junior water rights). Andersen does not expect to make a similar call on water on the upper Gunnison River side because of better snowpack, which should maintain higher flows there. He said the association would use that Gunnison water before resorting to a call on the Ouray side…

The last time that Ouray irrigators had to shut their headgates due to low stream flows and obligations to more senior water rights holders downstream was in 2012. That is when the Ouray County Water Users Association was founded…

With the drought conditions came concerns about wildfires, and Ouray and Montrose counties implemented Stage 1 Fire Restrictions on [May 21, 2018]. Stage 1 limits the areas where fires, smoking and spark-igniting activities can take place, according to the State of Colorado Department of Fire Prevention. Stage 2 adds more restrictions, while Stage 3 is the strictest, limiting entry into closed areas and setting fines as high as $10,000 for violators, or imprisonment for six months.

Aspinall unit operations update: Blue Mesa inflow forecast = 52% of 30 year average

Blue Mesa Reservoir

From email from Reclamation (Erik Knight):

The May 1st forecast for the April – July unregulated inflow volume to Blue Mesa Reservoir is 350,000 acre-feet. This is 52% of the 30 year average. Snowpack in the Upper Gunnison Basin peaked at 69% of average. Blue Mesa Reservoir current content is 496,000 acre-feet which is 60% of full. Current elevation is 7478.7 ft. Maximum content at Blue Mesa Reservoir is 829,500 acre-feet at an elevation of 7519.4 ft.

Based on the May 1st forecast, the Black Canyon Water Right and Aspinall Unit ROD peak flow targets are listed below:

Black Canyon Water Right
The peak flow target will be equal to 987 cfs for a duration of 24 hours.
The shoulder flow target will be 300 cfs, for the period between May 1 and July 25.

Aspinall Unit Operations ROD
The year type is currently classified as Dry.
There is no peak flow target in a Dry year category
Baseflow targets will continue to be met throughout the year.

Releases from the Aspinall Unit will be increased by 400 cfs on Monday, May 14th in order to allow the Black Canyon water right to be met. Flows on the North Fork of the Gunnison River are also predicted to be near peak levels at this time. The resulting flow on the lower Gunnison River at the Whitewater gage is estimated to be around 2500 cfs. On Tuesday, May 15th, releases from the Aspinall Unit will be decreased by 400 cfs to return river flow to the pre-peak level.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 890 cfs for May and 1050 cfs for June.

Currently, diversions into the Gunnison Tunnel are 1000 cfs and flows in the Gunnison River through the Black Canyon are 600 cfs. During the 1 day peak flow Gunnison Tunnel diversions will still be 1000 cfs and flows in the Gunnison River through the Black Canyon will be around 1000 cfs. River flows will return to 600 cfs the day after the peak flow. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: Gunnison Tunnel diverting for the season

Gunnison Tunnel via the National Park Service

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit have been increasing over the last couple weeks as diversions to the Gunnison Tunnel have begun. So far these release changes have kept the flows in the Gunnison River through the Black Canyon around 630 cfs. Diversions into the Gunnison Tunnel are expected to increase again this week. This time releases from Crystal Dam will remain unchanged and Gunnison River flows will decrease accordingly. It is expected that river flows will decrease by 100-200 cfs this week. Currently snowpack in the Upper Gunnison Basin is at 72% of normal. The latest runoff volume forecast for Blue Mesa Reservoir projects 360,000 AF of inflow between April and July, which is 53% of average.

Flows in the lower Gunnison River are currently above the baseflow target of 890 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 890 cfs for April and May.

Currently, diversions into the Gunnison Tunnel are 620 cfs and flows in the Gunnison River through the Black Canyon are around 630 cfs. By the end of the week Gunnison Tunnel diversions could be in the 700 to 800 cfs range and river flows could be in the 400 to 500 cfs range. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

#Snowpack news: Aspinall Unit operations update — 650 CFS in the Black Canyon

Looking downstream from Chasm View, Painted Wall on right. Photo credit: NPS\Lisa Lynch

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased by 100 cfs on Thursday, February 1st. Releases are being decreased in response to the very dry conditions and forecast for low spring runoff. Currently snowpack in the Upper Gunnison Basin is at 64% of normal. The latest runoff volume forecast for Blue Mesa Reservoir projects 420,000 AF of inflow between April and July, which is 62% of average.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for January through March.

Currently, diversions into the Gunnison Tunnel are at 0 cfs and flows in the Gunnison River through the Black Canyon are around 750 cfs. After this release change Gunnison Tunnel diversions will still be at 0 cfs and flows in the Gunnison River through the Black Canyon will be around 650 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: @USBR is drawing down Blue Mesa #ColoradoRiver #COriver

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased by 850 cfs between Friday, December 1st and Saturday, December 2nd. Releases are being increased as part of winter operations to lower the level of Blue Mesa Reservoir nearer to the winter elevation target as well as managing releases with consideration to wintertime hydropower demands.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for December.

Currently, diversions into the Gunnison Tunnel are at 0 cfs and flows in the Gunnison River through the Black Canyon are around 750 cfs. After this release change Gunnison Tunnel diversions will still be at 0 cfs and flows in the Gunnison River through the Black Canyon will be around 1600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: Gunnison Tunnel diversions ending for season

From email from Reclamation (Erik Knight):

On Wednesday, November 1st, diversions to the Gunnison Tunnel will end for the season. Releases from the Aspinall Unit will be adjusted in coordination with the ramp down schedule for Gunnison Tunnel diversions in order to keep Gunnison River flows near the current level of 750 cfs. There could be fluctuations in the river throughout the day until the Gunnison Tunnel is completely shut down.

On Thursday and Friday, November 2nd and 3rd, releases from the Aspinall Unit will be reduced to 300 cfs during the day time hours in order to allow for completion of the sonar survey of the Crystal Dam stilling basin. Gunnison River flows will drop down towards 300 cfs during the day while returning to 750 cfs during the non-working hours. After the sonar survey is completed at the end of the day on November 3rd, river flows will return to the current level of 750 cfs.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for October through December.

Currently, diversions into the Gunnison Tunnel are near 850 cfs and flows in the Gunnison River through the Black Canyon are around 750 cfs. After the shutdown of the Gunnison Tunnel and completion of the Crystal stilling basin sonar survey, flows in the Gunnison River through the Black Canyon will return to 750 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit operations update: Lower Gunnison streamflow above baseflow target

Fog-filled Black Canyon via the National Park Service

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased by 100 cfs on Thursday, October 12th. Diversions to the Gunnison Tunnel will be reduced by 100 cfs on Wednesday, October 11th so there will be a short period of flows over 1000 cfs in the Gunnison River through the Black Canyon before the river returns to a flow of 950 cfs by late Thursday morning.

Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for October through December.

Currently, diversions into the Gunnison Tunnel are near 975 cfs and flows in the Gunnison River through the Black Canyon are around 950 cfs. After this release change Gunnison Tunnel diversions will be about 900 cfs and flows in the Gunnison River through the Black Canyon will still be around 950 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.